Multi level sliding menu with jQuery

v1: vertical layout

This is the top level

Item 1
Item 2
Item 3

Level 1

Back to level 1

Item 1.1
Item 1.2
Item 1.3
Item 1.4
Item 1.5
Item 2.1
Item 2.2
Item 2.3
Item 3.1
Item 3.2
Item 3.3

Level 2

Back to level 2

Item 1.1.1
Item 1.1.2

Level 3

v2: horizontal layout

This is the top level

Item 1
Item 2
Item 3

Level 1

Back to level 1

Item 1.1
Item 1.2
Item 1.3
Item 1.4
Item 1.5
Item 2.1
Item 2.2
Item 3.1
Item 3.2
Item 3.3

Level 2

Back to level 2

Item 1.1.1
Item 1.1.2
Item 1.1.3
Item 1.1.4
Item 1.1.5
Item 1.1.6
Item 1.1.7

Level 3

This code applies to both v1 and v2.
v2 has additional CSS mentioned below.

HTML

CSS

CSS (v2)

JS